Added ChaCha20+Poly1305 support (stand-alone, cipher suites).

[BearSSL] / src / ssl / ssl_rec_chapol.c

diff --git a/src/ssl/ssl_rec_chapol.c b/src/ssl/ssl_rec_chapol.c
new file mode 100644 (file)
index 0000000..73b3c78
--- /dev/null
+++ b/src/ssl/ssl_rec_chapol.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining 
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be 
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+static void
+gen_chapol_init(br_sslrec_chapol_context *cc,
+       br_chacha20_run ichacha, br_poly1305_run ipoly,
+       const void *key, const void *iv)
+{
+       cc->seq = 0;
+       cc->ichacha = ichacha;
+       cc->ipoly = ipoly;
+       memcpy(cc->key, key, sizeof cc->key);
+       memcpy(cc->iv, iv, sizeof cc->iv);
+}
+
+static void
+gen_chapol_process(br_sslrec_chapol_context *cc,
+       int record_type, unsigned version, void *data, size_t len,
+       void *tag, int encrypt)
+{
+       unsigned char header[13];
+       unsigned char nonce[12];
+       uint64_t seq;
+       size_t u;
+
+       seq = cc->seq ++;
+       br_enc64be(header, seq);
+       header[8] = (unsigned char)record_type;
+       br_enc16be(header + 9, version);
+       br_enc16be(header + 11, len);
+       memcpy(nonce, cc->iv, 12);
+       for (u = 0; u < 8; u ++) {
+               nonce[11 - u] ^= (unsigned char)seq;
+               seq >>= 8;
+       }
+       cc->ipoly(cc->key, nonce, data, len, header, sizeof header,
+               tag, cc->ichacha, encrypt);
+}
+
+static void
+in_chapol_init(br_sslrec_chapol_context *cc,
+       br_chacha20_run ichacha, br_poly1305_run ipoly,
+       const void *key, const void *iv)
+{
+       cc->vtable.in = &br_sslrec_in_chapol_vtable;
+       gen_chapol_init(cc, ichacha, ipoly, key, iv);
+}
+
+static int
+chapol_check_length(const br_sslrec_chapol_context *cc, size_t rlen)
+{
+       /*
+        * Overhead is just the authentication tag (16 bytes).
+        */
+       (void)cc;
+       return rlen >= 16 && rlen <= (16384 + 16);
+}
+
+static unsigned char *
+chapol_decrypt(br_sslrec_chapol_context *cc,
+       int record_type, unsigned version, void *data, size_t *data_len)
+{
+       unsigned char *buf;
+       size_t u, len;
+       unsigned char tag[16];
+       unsigned bad;
+
+       buf = data;
+       len = *data_len - 16;
+       gen_chapol_process(cc, record_type, version, buf, len, tag, 0);
+       bad = 0;
+       for (u = 0; u < 16; u ++) {
+               bad |= tag[u] ^ buf[len + u];
+       }
+       if (bad) {
+               return NULL;
+       }
+       *data_len = len;
+       return buf;
+}
+
+/* see bearssl_ssl.h */
+const br_sslrec_in_chapol_class br_sslrec_in_chapol_vtable = {
+       {
+               sizeof(br_sslrec_chapol_context),
+               (int (*)(const br_sslrec_in_class *const *, size_t))
+                       &chapol_check_length,
+               (unsigned char *(*)(const br_sslrec_in_class **,
+                       int, unsigned, void *, size_t *))
+                       &chapol_decrypt
+       },
+       (void (*)(const br_sslrec_in_chapol_class **,
+               br_chacha20_run, br_poly1305_run,
+               const void *, const void *))
+               &in_chapol_init
+};
+
+static void
+out_chapol_init(br_sslrec_chapol_context *cc,
+       br_chacha20_run ichacha, br_poly1305_run ipoly,
+       const void *key, const void *iv)
+{
+       cc->vtable.out = &br_sslrec_out_chapol_vtable;
+       gen_chapol_init(cc, ichacha, ipoly, key, iv);
+}
+
+static void
+chapol_max_plaintext(const br_sslrec_chapol_context *cc,
+       size_t *start, size_t *end)
+{
+       size_t len;
+
+       (void)cc;
+       len = *end - *start - 16;
+       if (len > 16384) {
+               len = 16384;
+       }
+       *end = *start + len;
+}
+
+static unsigned char *
+chapol_encrypt(br_sslrec_chapol_context *cc,
+       int record_type, unsigned version, void *data, size_t *data_len)
+{
+       unsigned char *buf;
+       size_t len;
+
+       buf = data;
+       len = *data_len;
+       gen_chapol_process(cc, record_type, version, buf, len, buf + len, 1);
+       buf -= 5;
+       buf[0] = (unsigned char)record_type;
+       br_enc16be(buf + 1, version);
+       br_enc16be(buf + 3, len + 16);
+       *data_len = len + 21;
+       return buf;
+}
+
+/* see bearssl_ssl.h */
+const br_sslrec_out_chapol_class br_sslrec_out_chapol_vtable = {
+       {
+               sizeof(br_sslrec_chapol_context),
+               (void (*)(const br_sslrec_out_class *const *,
+                       size_t *, size_t *))
+                       &chapol_max_plaintext,
+               (unsigned char *(*)(const br_sslrec_out_class **,
+                       int, unsigned, void *, size_t *))
+                       &chapol_encrypt
+       },
+       (void (*)(const br_sslrec_out_chapol_class **,
+               br_chacha20_run, br_poly1305_run,
+               const void *, const void *))
+               &out_chapol_init
+};